Catheters provide minimally invasive means for treating various conditions. For example, angioplasty is a common procedure used to treat cardiovascular disease. During an angioplasty procedure, a medical device, such as a balloon catheter, may be percutaneously inserted into a vessel narrowed by stenosis. The balloon may be expanded at the stenosis to ultimately restore blood flow through the vessel. In some cases, a stent may be placed at the narrowed portion of the vessel to help keep the vessel open. In either case, it may be desirable to combine the balloon and/or stent treatment with the application of therapeutic drugs. In particular, it may be desirable to deliver a therapeutic drug exclusively to the narrowed portion of the vessel. In some cases, a therapeutic drug may be used to reduce restenosis at the treatment site.
A number of catheter devices have been developed to administer a therapeutic agent locally to tissue while dilating a body vessel, such as during delivery of a therapeutic agent to a dilated portion of a coronary artery in an angioplasty procedure. For instance, U.S. Pat. No. 8,182,446 to Schaeffer et al. discloses a catheter having a dual balloon assembly. The dual balloon assembly includes an inner balloon and a porous outer balloon concentrically arrayed around the inner balloon. Radial outward expansion of the inner balloon may urge the outer balloon into contact with the wall of a vessel, where a therapeutic agent may be delivered from the catheter through apertures in the outer balloon. Such a balloon catheter device is also referred to as a weeping balloon. Weeping balloons typically require a profile size sufficient to accommodate a wire guide lumen, an inflation lumen, and a drug delivery lumen. Although weeping balloons have definite advantages, it should be appreciated that there is a continuing need for improved catheter devices.
The present disclosure is directed toward one or more of the problems or issues set forth above.